One of the easiest ways to start securing your server (and speeding it up) is to turn off unnecessary services that are usually running by default. This little script will go through and turn off those services. Please read through the script to see what it is doing and comment out (put a # in front of the line) anything that you want to keep running.
I put little descriptions in front of each to help you determine what each service is/does. Copy this into a file called turn_off_services.sh and chmod +x it to make it executable. Then, just run it!
#!/bin/sh
# Script to disable unneeded services at boot time
# Please read through each to ensure you want these disabled.
# For /most/ systems, this set up is fine.
# anacron
# The anacron subsystem is designed to provide cron functionality
# for machines which may be shut down during the normal times that
# system cron jobs run, frequently in the middle of the night.
# Laptops and workstations which are shut down at night should keep
# anacron enabled, so that standard system cron jobs will run when
# the machine boots.
chkconfig anacron off
service anacron stop
# apmd
# APM is being replaced by ACPI and should be considered deprecated.
# As such, it can be disabled if ACPI is supported by your hardware
# and kernel. If the file /proc/acpi/info exists and contains ACPI
# version information, then APM can safely be disabled without loss
# of functionality.
chkconfig apmd off
service apmd stop
# autofs
# If the autofs service is not needed to dynamically mount NFS
# filesystems or removable media, disable the service
chkconfig autofs off
service autofs stop
# avahi-daemon
# The Avahi daemon implements the DNS Service Discovery and Multicast
# DNS protocols, which provide service and host discovery on a network.
# It allows a system to automatically identify resources on the network,
# such as printers or web servers.
chkconfig avahi-daemon off
service avahi-daemon stop
# bluetooth
# If the system requires no Bluetooth devices, disable this service
chkconfig bluetooth off
service bluetooth stop
# cups
# Do you need the ability to print from this machine or to allow others
# to print to it? If not:
chkconfig cups off
service cups stop
# gpm
# GPM is the service that controls the text console mouse pointer.
# (The X Windows mouse pointer is unaffected by this service.)
chkconfig gpm off
service gpm stop
# haldaemon
# The haldaemon service provides a dynamic way of managing device
# interfaces. It automates device configuration and provides an API for
# making devices accessible to applications through the D-Bus interface.
chkconfig haldaemon off
service haldaemon stop
# hidd
# If the system requires no Bluetooth devices, disable this service
chkconfig hidd off
service hidd stop
# kudzu
# Kudzu, Red Hat’s hardware detection program, represents an unnecessary
# security risk as it allows unprivileged users to perform hardware
# configuration without authorization. Unless this specific functionality
# is required, Kudzu should be disabled.
chkconfig kudzu off
service kudzu stop
# mcstrans
# Unless there is some overriding need for the convenience of category
# label translation, disable the MCS translation service
chkconfig mcstrans off
service mcstrans stop
# messagebus
# If no services which require D-Bus are in use, disable this service
chkconfig messagebus off
service messagebus stop
# nfs services
# If NFS is not needed, disable NFS client daemons
chkconfig nfslock off
service nfslock stop
chkconfig rpcgssd off
service rpcgssd stop
chkconfig rpcidmapd off
service rpcidmapd stop
# pcscd
# If Smart Cards are not in use on the system, disable this service
chkconfig pcscd off
service pcscd stop
# portmap
# No NFS, NIS? No portmap
chkconfig portmap off
service portmap stop
# xfs
# The system’s X.org requires the X Font Server service (xfs) to function.
# The xfs service will be started auto- matically if X.org is activated
# via startx. Therefore, it is safe to prevent xfs from starting at
# boot when X is disabled, even if users are allowed to run X manually.
chkconfig xfs off
service xfs stop
*taken from http://www.linuxbrigade.com/turn-off-unneeded-services-on-your-linux-machine/